Electric heater.



. PHELPS.

ELECTRIC HEATER.

APPLICATION FILED APR. 13. 1911.

Patented Sept. 14, 1915.

'111111/11 IIIIII/III/III/II/IIIIl/I/IllII sesame 1. rnnnrs, or nncnnnnn, rarest-sari.

ELECTRIC Specification of Letters Patent.

Sept. 14..

Application riled April 13, mil. Serial Itlo. 820,372.

To all whom it may concern Be it known that l. SEEKING If. Prrnnrs, a citizen of the United States of America, and a resident of Buchanan, county of derrien, State of Michigan, have invented certain new and useful Improvements in Electric Heaters, of which the "following is a specification.

The main objects of this invention are to provide an improved construction for electric heating elements to be used with electric cooking devices whereby'the devices will be rendered capable of more rapidly obtaining an operating heat and of operating at a greater efliciency than is the case with usual constructions; to provide an improved construction of the insulating member on which the resistance material is wound; and to provide an improved manner of winding the resistance material on said member.

An illustrative embodiment of this invention is shown in the accompanying draw ings, 1n wh1ch I Figure 1 is a detail of the heating element constructed according to this invention showing the method of winding the resistance material if the device is designed for a single operating temperature. Fig. 2 is a similar view illustrating the method of winding the resistance material when three distinct heats or temperatures are desired. Fig. 3 is a detail in perspective of the spring clip by which the sheets of insulating material and the heating element are held together. Fig. 4 is an enlarged fragmentary detail showing the clip as applied. 7

In the-construction shown in the drawing the heating element comprises a disk of insulating material 34, preferably mica, upon which is wound the electric resistance material 20, which in the drawings is shown as a flat ribbon of metal. This may be wound on the disk as a single winding, as shown in Fig. 1, or as plural winding, as shown in Fig. 2, according to the service for which the device is intended. The disk 3% has a large central aperture 35. A series of aper- I desired quantity ct the ribbon to make complete winding is passed repeatedly through the central aperture 35 and around one edge of the disk, each convolution of the ribbon being meanwhile passed sidewise in one of the slits 38 to its proper aperture and being then drawn taut so that it will be held in place by the apertures 36 and notches 37. As a rule, the apertures 38 and notches 37 are differently positioned when the disk is to be wound for obtaining single or multiple heats. For a one heat winding. a single wire or ribbon is used and adjacent convolutions arev seated in adjacent notches, the two ends being connected to two suitable binding posts when the element is assembled in the desired device. If three heats are desired, two separate windings are provided, the first wire being seated in alternate notches, and the second wire is wound in between the convolutions of the first. (lne end of each of the windings is con nected to the same binding post, and their other ends are connected to separate binding posts on said device.

The winding is preferably begun at or near the center of the disk and wound outwardly on one side of the slit 35, then back on the opposite side of the slit past the center and continuing to the other end of the slit, and finally crossing back to the first side and winding back to the center. this way the ends of the wires are at the center of the diskwhere they are conveniently connected to the contact members. The same system of winding applies to either single or multiple windings. If the heating element has a single windmg, it is necessary to provide only two pairs of binding'posts on the electric heating device of which it forms a part. If, however, the element has two windings, it is necessary to have three binding posts and the usual controlling switch is interposed in the circuit connecting the element with the source of electricity.

Theheating element 3 is placed between sheets of mica ll and 443* before being placed between the plates 1 and 2. These sheets and heating elements are secured together by means of a plurality of spring clips l5 so that they may be handled as a unit when removed from the plates 1 and 2 without danger of becoming displaced.

Although but one specific embodiment of this invention is herein shown and described,

it will beunderstood-that numerous details of the construction shown maybe altered or omitted without departing from the spirit of this invention, as defined by the following claims.

I claim 1. An electric heating device, comprising an integral sheet of insulating material having a relatively long and narrow slit therein, and resistance material Wound on said sheet from'said slit to the edges of said sheet at oppositesides, said convolutions extending insubstantially the same general direction transversely to said slit,

2. An electric heating device, comprising an integral disk of insulating material having therein a diametrically disposed relatively long and narrow slit, and resistance material Wound on said sheet from said slit to the edges of said disk which are on opposite sides of the slit.

' 3. An electric heating device, comprising an integral disk of insulating material having an aperture therein and having a slit extendingoutwardly from said aperture and terminating adjacent to the edge of said disk, and resistance material wound on said disk from saidslit and aperture to the'edges of said disk which are at both sides of said disk.

4. An electric heating device, comprising a disk of insulating material having a main aperture centrally located therein, a row of smaller apertures in said disk extending between said main aperture and the edge of said disk, said disk having a slit extending.

- along said row and connecting adjacent .apertures,'and resistance material wound on said disk from said apertures to the edges .an integral, disk of insulating material, re-

sistance material wound thereon so that the convolutions of the winding extend in opposite directions transversely to and on opposite sides of a diameter'of the disk, said winding beginning near the center of said disk, continuing outwardly in one direction, crossing said diameter and continuing in the reverse direction beyond the starting point, recrossing said diameter and continuing in said first direction to the starting point.

6. An electric heating device, comprising an integral disk of insulating material, resistance material wound thereon so that the convolutions of the winding extend in opposite directions transversely to and on opposite sides of a diameter of the disk, said winding beginning near the center of said disk, continuing outwardly in one direction, crossing said diameter and continuing in the reverse direction beyond the starting point, recrossing said diameter and continuing in said first direction to the starting point, "and a second winding of resistance. material having its successive convolutions interposed respectively between the successive convolutions of said first winding.

Signed at Chicago this 7th day of April, 1911.

SEBRING I. PHELPS.

Witnesses EDWIN PHELPS, MARY H. BIXEL. 

